I really respect your answer, but surely The Island of Sodor should be considered a separate canon rather than more canonical than The Railway Series? I don’t have a copy, given it’s sadly been out of print for around 40 years, but does it include things like talking, sentient, opinionated steam engines? ;)

Henry the Green Engine reads:

Then I expect you were sorry for Henry who was often ill and unable to work. He gave Sir Topham Hatt (who is, of course, our Fat Controller) a lot of worry. Now Henry has a new shape and is ready for anything. These stories tell you all about it.

“Cheer up, Henry! It wasn’t your fault. Ice and snow caused the accident. I’m sending you to Crewe, a fine place for sick engines. They’ll give you a new shape and a larger firebox. Then you’ll feel a different engine, and won’t need special coal any more. Won’t that be nice?” “Yes, sir,” said Henry doubtfully.

Henry liked being at Crewe, but was glad to come home.

He is clearly the same Henry in terms of personality and memories, post-rebuild, even if he has miraculously morphed into a Black 5. If The Island of Sodor takes a more realistic approach, that’s fine, but even your quote says “rebuilt” instead of “scrapped”.

That Thomas-as-the-ship-of-Theseus meme that did the rounds on Lemmy the other week springs to mind…

See also: https://en.wikipedia.org/wiki/And_Then_There_Were_None (Agatha Christie, 1939)

No, he’s sent to Crewe for a rebuild and returns with a new shape - mostly changes to his firebox iirc as he’s been struggling to build up enough steam with anything other than high-quality (expensive) Welsh coal.

Source: literally re-read the relevant book over the weekend.

He unleashed his Little Boy all over Hir! (oshima)